A driver IC module having multiple high breakdown voltage drivers and an overtemperature detection circuit is proposed in Japanese Patent Application JP-A-2001-244411. The overtemperature detection circuit detects an overtemperature condition of a driver IC chip based on a difference between a temperature of the IC chip and a reference temperature. The reference temperature is altered according to a temperature of the driver IC module so that the detection is accurately performed without an influence of ambient temperature.
An overtemperature detector having a band gap circuit that produces a reference voltage used in a production of an overtemperature detection signal is proposed in Japanese Patent Application JP-A-7-336875. In the band gap circuit, a component that outputs a temperature-dependent potential difference functions as an overtemperature detection component. The overtemperature detection signal is used for maintaining a predetermined accuracy in the overtemperature detection without affected by manufacturing variations.
In an IC device having an overtemperature detection circuit for each driver IC such as the above-described driver IC module, a temperature increase in the driver IC may affect an adjacent overtemperature detection circuit of another drive IC. For instance, the adjacent overtemperature detection circuit may falsely detect an overtemperature condition when a load connected to the driver IC is shorted and the temperature increase occurs.
This problem may be solved by arranging the driver ICs at a distance from each other. However, the overall chip size of the device increases and therefore the cost of the device increases. The same problem occurs in the case of a device constructed of multiple discrete power components adjacently arranged to each other.